...or adding fuel to the fire?
The 851 was fresh off that top end rebuild to set the squish, new eprom fitted with extended redline, a dyno tune to suit, and we'd lost or redistributed a few kg's. In your best British "chav" accent: "Cor, she looks fit!"
So my roster finally aligned with a trackday, the weather looked great and I was busting to see how it all felt. No back-up bike/plan, just me, my girl, and some Daddy time.
This being a Trakdayz event they provide coaching through the levels, from Group 1 (introduction) to Group 3 (advanced) while Group 4 is the racers who are left to their own devices. I've leapt in with the racers on the R1 before and had a good day, but there's still a certain amount of performance pressure having been out of it for so long, so I'd opted for a stress free Group 3. Not to mention a few pointers from the rider coaches never goes astray. It really is good value:
So the first session was a simple "no-brakes" exercise just to ease folks into it and get our heads in the game. This is where a twin is quite good with engine braking a very handy thing! Some folks can't help themselves and just want to go nuts from the off, so you see plenty of them using far more brakes than they should rather than concentrating on corner entry speed which is the aim of the exercise.
But I got through most of the exercise fine, until right near the end one of the instructors passes me and waves me into the pit entrance: he'd seen a bit of smoke from the bike, nothing major, was I aware? Of course I wasn't, so into the box I trundle, fairings off, and I start checking things out.....but there's nothing to see. There's no evidence of oil anywhere except a drop of oil on the gear selector shaft, could that be dripping on the exhaust? A few big free rev's show no smoke, so I'm at a bit of a loss to explain it.
Next session is a more normal "set your own pace" effort. I pass more bikes than pass me so all good, but there were a few issues that I started mentally noting:
- the brakes, despite a solid effort trying to convince myself they just needed a big squeeze, are just crap. You spend far too much of your concentration telling your usually lazy last 2 fingers to get on the lever and help out 'cos the usual 2 fingers just weren't cutting it: a big four finger squeeze is great for crushing beer cans but not so much for fine modulation.
- the single compound Renthal grips were too thin/small; not a comfortable grasp and losing leverage on what was a stiff throttle courtesy of the single cable system and quick-turn Electraeon throttle cam. It was just more drain on my limited bandwidth having to continually ensure full gas wasn't just 85% gas.
- the Jenny Craig weight-loss program plus some anti-slosh fuel tank foam had taken years off the ol' girl. Not a night vs day difference but noticeably more modern with the centre of mass moved a tad further forward, more eager looking for that apex.
All in all she felt great, pulling way harder than more than a few modern pilots expected and handled nothing like a 30 year old bike, she just need a few minor quibbles sorted to join what were some good looking dots.
There I was jotting down mental notes when an instructor pulls alongside and gesticulates in no uncertain terms to get off the racing line. Obviously my mind instantly jumped to the oil/smoke issue and I did exactly that, cruising back into the pits...gutted. WTF was it this time?
I'd barely climbed off the bike and it was plain to see what had caused the consternation, the whole side of the bike was covered in oil:
With a fair puddle forming under the poor ol' girl and oil burnt onto the exhaust:
There wasn't going to be a miracle cure trackside so there was nothing for it but to pack up and drive very slowly, very quietly, back home.
As bad as it looked tearing it down the next day I couldn't help thinking I'd actually dodged a bullet, with the instructor doing me a huge favour in getting me off the track when he did: things were on the verge of being much much worse if that oil got on the rear tyre:
I thought I'd sorted the bloody breather problem and the bike had absolutely no issue being hammered on the dyno, what the hell was going on?
Yet, the evidence of oil being pumped from the crankcase was in front of me, far worse than before. I didn't get a good photo of the oily airbox, but the whole thing was just a Deep Water Horizon-style mess :
A compression test was revealing, the horizontal cylinder down 20psi on the vertical.
Stepping up to a leakdown test, was even more enlightening, with air audibly escaping from the oil filler cap => piston ring issue.
Here we go again: exhaust off, airbox and throttle bodies off, cam belt off, side cover off, head off, barrel off (scored, bugger), piston off....and we can finally inspect the rings:
Yup, that'll do it...
I had some spare rings available, but the cylinder was more than just marked, you could feel the scuffing/scoring so off it went to Electrosil in Melbourne for repair/replating.
They really do a stellar job, requesting you send a piston to accompany the barrel which ensures accurate sizing, and turning them around quick-smart. They come back honed/cross hatched ready to go and literally looking better than new.
I had the barrel back 2 weeks later, and not long after that she was back together. Now what? I effectively had to run the thing in again....but how?
Caution: this is a hugely contentious subject!
So I'm not going to elaborate too much here, there is plenty of info out there you just need to follow what makes sense to you. The philosophy below makes sense to me, and ties in with a lot of my trade training around plain bearings (albeit on gas turbines and high-speed geared pumps etc) that run on an oil "wedge", there is no metal on metal contact that requires molly coddling, so this is what I followed to bed in the rings:
